1. Field of the Invention
The present invention relates to hand rails used to support and balance pedestrians walking on stairs, ramps, or other uneven or slippery surfaces on which they may inadvertently lose their balance. More particularly, the present invention relates to a composite hand rail having a pleasing appearance, strong enough to achieve the traditional support functions of a hand rail, yet capable of being readily fabricated into designer specified curvilinear shapes.
2. Description of the Related Art
Hand rails are used to aid pedestrian balance when walking. Hand rails are commonly found on stairs and ramps having residential, commercial, and industrial applications. Building codes may require hand rails for stair and ramp applications.
Stairs and ramps often comprise of multiple flights thus requiring hand rails that are rectilinear or curvilinear. In these applications, the hand rail follows the perimeter of the stair or ramp. The hand rail must then negotiate corners that are commonly ninety degrees but may be nearly any imaginable angle.
Conventional hand rails are fabricated of straight lengths joined by curved or angled members that negotiate changes in height or direction. Goosenecks may join rising sections to horizontal sections and curved joinder pieces may link two straight sections as the rail passes around a corner. Decorative spiral shapes such as bullnoses or volutes provide ornamental beauty to hand rails. Depending on the complexity of the stair case, hand rails may also have gently curving or even spiral shapes. Curving or spiral shapes are complex, difficult and costly to manufacture. Problems are exacerbated if the shapes or curves are of varied increasing or decreasing radius and not constant radius sections.
Hand rails are typically fabricated of wood or metal sections. Metal sections are more common in industrial or commercial applications where strength and reliability is important. Wood is more common in residential applications where appearance becomes relatively more important.
Metal sections are best and most easily fabricated in straight lengths. Curvilinear sections such as volutes can be fabricated, however, such fabrication is costly. Joiner pieces such as over easings and quarter turns may be welded, wrought or cast. Balusters, and newel posts may be easily fabricated of the same metal. Metal hand rail sections are heavy and require adequate support from balusters, newel posts, or wall mounted hangers. When supported only by wall mounted hangers, the weight of metal railings requires consideration of wall fasteners and the distance between the hangers.
Wood systems are in wide use as structural and ornamental railings for residential and commercial applications. Wood is less rigid than metal and must be supported by balusters or wall hangers at more frequent intervals than metal railings. Straight wood sections are easily milled but, forming complex wooden curvilinear shapes such as bullnoses, volutes, and goosenecks is difficult and costly.
What is needed is a visually pleasing system that simulates the appearance of wood yet has strength and rigidity in long sections and that can be readily fabricated into simple or complex curvilinear or rectilinear shapes.
Wiebe, U.S. Pat. No. DES 379,244, shows a hand rail of indeterminate length having a uniform cross section. The top surface is wider than the central portion and the structure flares out at the bottom of the rail.
Wonderly, U.S. Pat. No. DES 344,141, teaches a composite rail having vertical laminations that contribute to a wood grain effect of the rail when viewed from the side. The bottom view shows an edge grain while the top of the rail capped with another thin section. The overall ornamental appearance of the rail is that of multiple wood grains in a typically shaped hand rail.
Binder, U.S. Pat. No. 4,216,634, discloses a composite building column in which a plurality of thin walled hollow shells are filled with a core material such as plastic foaming material. The shell is formed from a sheet of lightweight material such as aluminum.
DenAdel, U.S. Pat. No. 5,678,381, teaches an insulated composite beam that is formed by enclosing an elongated plastic member with structural channels.
Although the prior art apparatus solved their specific ornamental and structural goals, the inventors did not address the problems encountered by attempting to provide a simulated wooden appearance, curvilinear shaping ability, and sufficient structural rigidity at a reasonable cost.